Article actuated pneumatic separator



Nov. 4, 1969 M. CALISTRAT 3,476,380

ARTICLE ACTUATED PNEUMATIC SEPARATOH Filed Dec. 15, 1967 2 Sheets-Sheet1 FIG. I

46 FIG. INVENTOR.

34 Mme-A cAL/sreAT 26 I I BY Nov. 4, 1969 M. CALISTRAT ARTICLE ACTUATEDPNEUMATIC SEPARATOR Filed Dec. 15, 1967 2 She ets-Sheet Z 7' III-P40FIG. 4v

A R IIIIIIIIJ VIIIIIIII %R r /Y m FIG. 5C

INVENTOR.

M/PCEA CALISTAAT BY K12 6601.74

United States Patent O 3,476,380 ARTICLE ACTUATED PNEUMATIC SEPARATORMircea Calistrat, Pikesville, Md., assignor to Koppers Company, Inc., acorporation of Delaware Filed Dec. 15, 1967, Ser. No. 691,014 Int. Cl.B65h 1/06, 3/08 US. Cl. 27132 7 Claims ABSTRACT OF THE DISCLOSURE Apneumatic separator for separating a single sheet or blank from a supplyfor transfer to subsequent processing apparatus. The separator comprisesa hollow, open-ended piston that slides within a continuously evacuatedcylindrical sleeve which has resilient means for urging the pistonoutwardly against a stop limiting such outward movement. In its outwardposition, the piston engages the single lower Sheet or blank, therebyclosing the end of the piston to atmosphere. The evacuation then causesthe piston to withdraw within the sleeve to separate the article that isadhering to the piston from the supply and to position the article fortransfer by associated transfer apparatus.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates generally to the feeding or delivering of sheet or blanks andmore particularly to pneumatic separators for a multiple sheet supply.

Description of the prior art Suction means for separating single sheetsor blanks from a supply have been of two types. They have been operativeeither (1) to lift the uppermost blank from the pack and advance orplace it in position for advancement by associated transfer means or (2)to separate the bottommost blank from the pack for similar advancement.The latter type is particularly useful in separating blanks which arewarped in either the direction of advancement or transverse thereto orboth.

The types which lift and/or advance the uppermost blank are usuallyprovided with suction cups which are mechanically moved by suitablelinkages into engagement with the top blank of the pack whereupon thesuction cups adhere to the blank and separate it from the pack as thecups are retracted. The cup may, itself, pivot to advance the adheringblank or a separate pusher element may thereafter advance the blank. Ineither event, it is usually necessary to provide means, such as valves,to break the vacuum between the cup and the blank to permit advancement.Devices of this type are subject to considerable wear because of thenumber of moving parts and the production speeds at which they mustoperate. Spiess Patent No. 3,000,629 illustrates a vacuum cup utilizingtwo suction zones, both of which are evacuated for separation of thetopmost blank from a pile. When the blank has been raised to thetransfer position, vacuum is broken to the stronger of the suction zonesby closing the entrance port to the zone by bottoming a piston withinits casing or sleeve.

On the other hand, suction devices operative to separate the bottommostblank from a pack are usually of the fixed type; i.e., a vacuum port isprovided in the bed-plate which supports the pack. If the blanks of thepack are warped, they do not lie flat against the bed-plate so it isdiflicult to transfer or feed the blanks sequentially through a meteredopening in register with associated processing machinery. Fixed suctiondevices are helpful in drawing the warped blanks against the bed-platebut they are not always positive so that jam-ups can occur when thetrans- 3,476,380 Patented Nov. 4, 1969 ice fer device attempts to feed ablank through the metered opening. An example of this type suctiondevice is found in Bishop et =al. Patent No. 3,105,681 which also uses areciprocable suction device to separate the lowermost blank from thepack and advances the blank through a metered opening.

SUMMARY OF THE INVENTION Accordingly, an object of the present inventionis to provide a pneumatic separator actuated by the blank to beseparated from a pack which is both simply constructed and reliable.Complex valving arrangements are not necessary to break the suctionforce between the separated blank and the pneumatic separator. This isgenerally accomplished by providing an open-ended piston slidably nestedwithin a cylindrical casing or sleeve and having resilient means forurging the piston outward from the sleeve, and into subatmosphericengagement with a blank to be separated from a pack. Evacuation meansare provided for automatically creating a suction within the piston uponits engagement with the blank which is operative to telescope the pistonwithin the sleeve thereby drawing or separating the blank from the pack.The invention is operative in conjunction with conventional adjacenttransfer means for feeding the separated blank through a metered openingand into subsequent processing machinery.

The above and further objects and novel features of the invention willappear more fully from the following detailed description when the sameis read in connection with the accompanying drawings. It is to beexpressly understood, however, that the drawings are not intended as adefinition of the invention but are for the purpose of illustrationonly.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings wherein like parts aremarked alike:

FIGURE 1 is a side elevation in cross-section of the pneumatic separatorshowing the piston engaging the lowermost blank of a pack prior toseparation;

FIGURE 2 is similar to FIG. 1 and shows the lowermost blank subsequentto separation from the pack but prior to feeding or transfer through ametered opening;

FIGURE 3 is a cross-section of the pneumatic separator taken along theline IIIIII of FIG. 1;

FIGURE 4 is an end elevation of a series of the pneumatic separatorsengaging the lowermost blank which is shown warped transverse to thetransfer or feed path of the blank;

FIGURES 5A, 5B, and 5C are schematic illustrations of the sequence ofoperation of the separators during a typical feed cycle; and

FIGURE 6 illustrates an optional locking feature to deactivate theseparator.

DESCRIPTION OF THE PREFERRED CONSTRUCTION The novel pneumatic separatorassembly 10 is illustrated in FIG. 1 as being associated with aconventional packsupporting bed-plate 12 adjacent the forward or leadingedge 14 of the lowermost blank 16 of pack 18. A conventional gate 20above the bed-plate 12 is vertically adjustable in the known manner todefine a metered opening 13 of the required size between the gate 20 andbed-plate 12 to permit only one blank at a time to pass therethrough. Asshown in FIG. 5, the blanks of pack 18 are often warped in the directionof feed of the blanks, and the leading edges 14 of the blanks that restagainst the face of gate 20 are likely to be spaced above the topsurface of bed-plate 12. Any attempt to feed the lowermost blank 16through the metered opening 13 without employing the novel separatorassembly 10 will merely jam the leading edge 14 into the face of gate20.

The separator 10 of this invention draws the leading edge 14 oflowermost blank 16 downward against the top surface of bed-plate 12, asillustrated in FIG. 2 so that the feeding mechanism will engage thetrailing edge of the blank and advance it through opening 13 until it isgripped by a pair of pull rolls 22, as seen in FIG. C. Rolls 22 advancethe blank into adjacent processing machinery (not shown). When thetrailing edge of the lowermost blank clears the separator 10, theseparator is again operative to draw the next lowermost blank downwardagainst the fbed-plate 12 and the sequence is repeated.

Referring now to FIGS. 1 and 3, separator comprises a tubular piston 24that is open on both ends and is slidably positioned within a casing orsleeve 26. Sleeve 26 is secured in any convenient manner such as, forexample, by a press-fit in a hole 28 in bed-plate 12. The upper end ofsleeve 26 is preferably flush with the top surface of bed-plate 12. Thelower end of sleeve 26 is joined to a transverse duct or header 30 by,for example,

welding. A hole 32 is provided in header 30 so that a path is providedfor the flow of air from the upper end of piston 24' into header 30.

A tension spring 34 urges piston 24 upwardly against the lowermost blank16. Spring 34 is provided with conventional end loops 36 which surroundan upper pin 38 and a lower pin 40. These pins 38 and 40 are preferablyprovided with reduced diameter reliefs 48 to retain spring 34 centrallywithin piston 24. As best illustrated in FIG. 3, lower pin 40 ispositioned in a pair of diametrically aligned holes 42 in piston 24, andupper pin 38 is positioned in a pair of diametrically aligned holes 44in sleeve 26 so that it remains fixed. Pin 38 extends through a pair ofdiametrically aligned longituidnal slots 46 provided in piston 24. Thetension of spring 34 pulls pin 40 upward, carrying the piston 24 withit, to the position shown in FIG. 1. If no blanks are lying on bed-plate12, the piston 24 will extend upward until pin 38 bottoms in slots 46.

Of course, other means may be utilized to urge the piston upward againstthe lowermost blank. For example, a coil compression spring ofapproximately the same diameter as the piston 24 may be placed betweenthe piston 24 and the header 30. Another example is a metal bellows ofapproximately the diameter as the piston 24 placed between the pistonand the header.

The sleeve 26 is preferably made of metal. Although the piston 24 mayalso be made of metal, it is preferably made of a rigid plastic such asplexiglass so that if any accidental breakage occurs, the piston willbreak rather than the sleeve. The pistons are relatively inexpensive andmay be easily replaced.

The blanks may be warped transverse to the direction of advancement asillustrated in FIG. 4. So that the leading edge 14 of blank 16 will bedrawn against the bedplate 12 beneath the gates 20, of which there areusually two, it is preferable to provide a separator 10 in longitudinalalignment with each gate. Since the gates are transversely adjustable toaccommodate wide blanks, as shown by the phantom lines in FIG. 4, twomore separators may be provided in alignment with the outward positionsof the gates. When the outermost separators are not being used, as whennarrower blanks are fed, a. scrap piece of paperboard can be placed overthem to prevent the loss of suction. The suction will maintain thepistons 24 in the down position without the need for fastening the scrappaperboard to the bed-plate 12.

The sleeve 26 of each separator 10 may be joined to header 30 aspreviously described. A conventional electrically operated blower 50 isconnected to the header 30 in the ordinary manner to provide a vacuumtherein and consequently in the sleeves 30, The amount of vacuum orsuction is preferably equal to about four inches of water although aslittle as three or as much as eight inches will operate the separators10 in a satisfactory manner when the blanks are ordinary corrugatedpaperboard. At less than three inches of water, the suction may beinsufficient to insure that the leading edge 14 will be drawn downcompletely against the bed-plate 12. At more than eight inches, itbecomes diflicult to slide the blank across the top of the separator 10.It should be understood that the suction pressure can be changed to suitthe need when separating blanks of other materials.

The transfer or feed mechanism illustrated schematically in FIG. 5 is ofa conventional reciprocating type. The feed mechanism as illustratedherein is, for example, the type described in Schulz Patent No.3,038,720 wherein a number of back-stops 52 are spaced across atransverse bar 54 to support the trailing edges of the pack 18 above thebed-plate 12 and to provide a space beneath the pack for reciprocatingspring feeders 56 that include lip portions 60 adapted to engage thetrailing edge of the lowermost blank when the feeders are in the rearposition. The bar 58 supporting the feeders 56 is reciprocated in theconventional manner. Both bars 58 and 54 can be positioned toward andaway from the gate 20 to provide for different length packs.

In operation, as seen in FIG. 1, the tension of spring 34 urges piston24 upwards until it engages the bottom of the lowermost blank 16. Theblank 16 closes the end of piston 24 to atmosphere. Suction pressure insleeve 26 and piston 24 overcomes the slight tension in spring 34 sothat piston 24 is drawn downward and within sleeve 26, drawing blank 16with it to the position shown in FIG. 2. At this time, the feeders 56are advanced in the normal manner thereby pushing the blank forward, asseen in FIG. 5C, until it is gripped by the pull rolls 22. The pullrolls continue to advance the blank as the feeders 56 return toward thefeeding position, FIG. 5A. Concurrently, piston 24 will again rise asthe advancing blank clears it since the top of the piston is again opento atmosphere. As soon as the piston 24 engages the next lowermostblank, it will draw it downward, as previously described, to the feedingposition, FIG. 5B, Thereafter, the cycle is repeated.

In ordinary suction devices, it is usually necessary to break thesuction between the blower, or vacuum pump as the case may be, and theblank engaging member to permit the blank to be advanced. This needusually requires the use of complex valving or venting arrangementswhich are subject to wear. The present invention does not require these.When the piston 24 approaches the lowermost blank, even a low suctionpressure is sufiicient to draw the .blank downward against it, even ifthe blank is not parallel to the top of the piston, see FIG. 1. When theblank is drawn against the bed-plate 12, the pressure acting on top ofthe blank merely presses it against the bed-plate. The only pressurebetween the blank and the piston is the slight amount needed to overcomethe tension of spring 34. Thus, the piston is subject to very littlewear. The difference in pressure reacts only between the bed-plate andthe blank. This pressure is easily overcome by the feeders 56 whichslide the blank across the upper surface of the bed-plates. Since theblank is pressed against the large surface of the fbed-plate 12, nounwanted scuffing of the blank will occur.

FIG. 6 illustrates a locking feature to deactivate piston 24 which maybe used should it be desired to operate the feeder without the use of avacuum or with the vacuum as an assist but without the pistons. The lockcomprises a circumferential slot 62 formed at a right angle to the topof each slot 46 as illustrated. Thus, by depressing the piston 24 andgiving it a slight twist, slot 62 will be positioned over the pin 38 andprevent extension of the piston. The tension of spring 34 maintains thepiston in the locked position. Twisting the piston in the oppositedirection will unlock it.

Thus, the present invention provides a simple, positive-operatingpneumatic separator which is actuated by contact with the blank. Becauseof its construction, very law suction pressure is required. It issubject to very little wear since the sliding friction between thepiston 24 and the blank is reduced by the suction pressing the blankagainst the bed-plate 12 rather than against the piston. The piston,because of its construction, has a very small mass, hence. a lowinertia, so that it operates rapidly. For example, in actual commercialuse, four separators of the type described herein have operatedsuccessfully in a printer-slotter machine feeding blanks at the rate offour per second with a suction pressure equal to four inches of waterwhile requiring only two horsepower to operate the blower to displaceapproximately eighty cubic feed of air per minute per piston.

Having thus described the invention in its best embodiment and mode ofoperation, that which is desired to be claimed by Letters Patent is:

1. Apparatus for feeding blanks sequentially from a supply of suchblanks, comprising:

a support for said supply of blanks;

gate means defining a metered opening with said support for limiting thefeeding of blanks therethrough to one blank at a time; suction means insaid support for separating a single blank from the bottom of saidsupply and positioning the leading edge of said blank against said support for entry into said metered opening; and

reciprocating advancing means for engaging the trailing edge of saidblank to advance it through said metered opening.

said suction means including a tubular piston having one end incommunication with an air evacuating means and a blank engaging end,resilient means for biasing said piston toward said supply so that saidpiston is closed to atmosphere by engagement with said single blankcausing it to adhere to said piston and causing said piston to movetoward said one end.

2. The apparatus of claim 1 wherein said suction means includes asleeve, said tubular piston lying within said sleeve and said resilientmeans urging said piston to extend beyond the end of said sleeve intoengagement wit-h said supply and said piston being adapted to telescopewithin said sleeve when said blank engaging end is closed to atmosphereby said blank, said air evacuating means operative to hold said blankagainst said sleeve when said piston is telescoped within said sleeve.

3. The separator of claim 2 wherein said resilient means includes:

a first member connected to said sleeve and held in a fixed positionthereby;

a second member connected to said piston and movable therewith; and

spring means connected to said first and second members for urging saidsecond member toward said first member for extending said piston beyondthe end of said sleeve.

4. The separator of claim 3 wherein said first and second members arepins secured in diametrically aligned apertures in said sleeve and saidpiston, said piston including diametrically aligned axially elongatedslots in the wall thereof through which said first member ex tendsproviding a stop to limit the extension of said piston beyond the end ofsaid sleeve.

5. The separator of claim 4 wherein said elongated slots include atransverse slot formed in said piston substantially perpendicular to oneend of said elongated slots adapted to receive said first member whensaid piston is rotated in the telescoped position to retain said pistonin said telescoped position.

6.'The separator in claim 1 wherein said piston is made of a rigidplastic material.

7. Apparatus for separating a single corrugated blank from'the bottom ofa stack of blanks and transferring it to subsequent processing machinerycomprising:

a bed plate for supporting said stack of blanks;

a gate mounted above said plate a space of one blank to limit themovement of said stack so that only one blank at a time can pass throughsaid space,

feed means at the rear end of said blanks and opposite from said gatefor engaging and urging the lowermost one of said blanks through saidspace,

said blanks being susceptible to warping whereby the front end of saidlowermost one of said blanks that is adjacent said gate lifts from saidbed and said blank tends to jam against said gate instead of passingthrough said space, and

suction means for pulling the front end of said blank against said bedto insure passage of said blank through said gate including:

an aperture in said bed adjacent said gate, a piston reciprocal in saidaperture, resilient means urging said piston to extend through saidaperture and into engagement with the front end of the lowermost one ofsaid blanks whereupon the end of said piston becomes closed by saidblank, and suction means operable upon the closing of said piston forretracting said piston into said aperture to pull the front end of saidlowermost blank against said bed, whereby the urging of said feed meanswill pass said lowermost blank through said space between said gate andbed.

References Cited UNITED STATES PATENTS 906,827 12/1908 Staude 27l-44EDWARD A. SROKA, Primary Examiner US. Cl. X.R. 27 l44

